In recent years, there has been progress in the development of light-emitting devices having light-emitting units using organic EL (Organic Electroluminescence) elements. The organic EL element is configured of an organic layer interposed between a first electrode and a second electrode. Since the organic layer is easily affected by moisture, oxygen or the like, the light-emitting unit needs to be sealed. One of the ways to seal the light-emitting unit is by using a sealing layer. Ways to form the sealing layer include gas phase film formation methods such as ALD (Atomic Layer Deposition), CVD, sputtering or the like.
Meanwhile, using a resin substrate as a substrate of the organic EL element is being considered. Using the resin substrate allows the light-emitting unit to have flexibility. However, resin materials transmit moisture. When moisture reaches the organic layer of the organic EL element, the organic layer is deteriorated, attributing to the moisture. To avoid such deterioration, forming a gas barrier film over the resin substrate is considered. For example, Patent Document 1 discloses a gas barrier film configured by laminating an inorganic film and a stress relaxation film. The stress relaxation film is formed by an atmospheric plasma treatment. Moreover, Patent Document 1 describes that a sealing film for sealing the organic EL element may be formed in the same way as the gas barrier film.